Surgical instrument with flexible shaft and actuation element guide

ABSTRACT

A surgical instrument includes a shaft, a force transmission mechanism disposed at a first end of the shaft, an end effector disposed at a second end of the shaft, an actuation element that extends along the shaft from the force transmission mechanism to the end effector, and an actuation element guide extending along the shaft. The actuation element guide defines a lumen in which the actuation element guide is received. The actuation element guide is compressed into a pre-compressed state along at least a portion of an axial length of the shaft. The actuation element guide can be compressed between first and second blocks of the instrument. The instrument can include a flush tube configured to receive a cleaning fluid, with the actuation element guide being in flow communication with the flush tube to receive the cleaning fluid in the lumen of the actuation element guide.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.14/864,272, filed Sep. 24, 2015, which claims priority to U.S.Provisional Application No. 62/056,232, filed Sep. 26, 2014 (nowexpired), each of which is incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present disclosure relates to surgical instruments that includeflexible shafts and actuation element guides, and to related systems andmethods.

BACKGROUND

Remotely controlled surgical instruments, including manually operated(e.g., laparoscopic) and teleoperated (e.g., robotically controlled)surgical instruments are often used in minimally invasive medicalprocedures. During medical procedures, surgical instruments may be movedin one or more degrees of freedom. For instance, the surgical instrumentmay be actuated by transmitting forces from a force transmissionmechanism at a proximal end of the surgical instrument shaft to orientand position an end effector located at a distal end of the surgicalinstrument in a desired location. The surgical instrument may furtherinclude a wrist, such as a jointed, articulatable structure, that theend effector is connected to so that the end effector may be positionedrelative to the shaft. The surgical instrument may further include oneor more actuation elements that extend from the force transmissionmechanism and pass through the surgical instrument to actuate the endeffector and/or a wrist.

Surgical instruments may be used with cannulas comprising a curvedsection. To insert a surgical instrument through the curved section to asurgical site within a patient, the shaft of the surgical instrument canbe flexible but also provide a degree of stiffness to support thesurgical instrument, and in particular the end effector, to perform asurgical procedure. It may be desirable to provide surgical instrumentconfigurations that address challenges associated with advancing asurgical instrument through a cannula having a curved section during aminimally invasive surgical procedure.

SUMMARY

Exemplary embodiments of the present disclosure may solve one or more ofthe above-mentioned problems and/or may demonstrate one or more of theabove-mentioned desirable features. Other features and/or advantages maybecome apparent from the description that follows.

In accordance with at least one exemplary embodiment, a surgicalinstrument comprises a shaft, a force transmission mechanism disposed ata first end of the shaft, an end effector disposed at a second end ofthe shaft, an actuation element that extends along the shaft from theforce transmission mechanism to the end effector, and an actuationelement guide extending along the shaft. According to an exemplaryembodiment, the actuation element guide defines a lumen in which theactuation element guide is received. According to an exemplaryembodiment, the actuation element guide is compressed into apre-compressed state along at least a portion of an axial length of theshaft.

In accordance with at least one exemplary embodiment, a surgicalinstrument comprises a shaft, a force transmission mechanism disposed ata first end of the shaft, an end effector disposed at a second end ofthe shaft, an actuation element that extends along the shaft from theforce transmission mechanism to the end effector, and an actuationelement guide extending along the shaft, a first block, and a secondblock. According to an exemplary embodiment, the actuation element guidedefines a lumen in which the actuation element guide is received. Thefirst block holds a first end of the actuation element guide, accordingto an exemplary embodiment. The second bock holds a second end of theactuation element guide, according to an exemplary embodiment. Theactuation element guide extends along a path that deviates from astraight path between the first and the second block, according to anexemplary embodiment.

In accordance with at least one exemplary embodiment, a method ofmanufacturing a surgical instrument that comprises a shaft, a forcetransmission mechanism at a first end of the shaft, an end effector at asecond end of the shaft, and an actuation element operably coupling theforce transmission mechanism and the end effector, comprises providingan actuation element guide through which the actuation element extendsalong the shaft. The method further comprises longitudinally compressingthe actuation element guide into a pre-compressed state along at least aportion of an axial length of the shaft.

In accordance with at least one exemplary embodiment, a surgicalinstrument comprises a shaft, a force transmission mechanism disposed ata first end of the shaft, an end effector disposed at a second end ofthe shaft, an actuation element that extends along the shaft andoperably couples the force transmission mechanism and the end effector,and an actuation element guide extending along the shaft. According toan exemplary embodiment, the actuation element guide defines a lumen inwhich the actuation element guide is received. According to an exemplaryembodiment, the force transmission mechanism comprises a flush tubeconfigured to receive a cleaning fluid. The actuation element guide isin flow communication with the flush tube to receive the cleaning fluidin the lumen of the actuation element guide, according to an exemplaryembodiment.

In accordance with at least one exemplary embodiment, a method ofmanufacturing a surgical instrument that comprises a shaft, a forcetransmission mechanism at a first end of the shaft, an end effector at asecond end of the shaft, and an actuation element operably coupling theforce transmission mechanism and the end effector, the method comprisingproviding an actuation element guide that defines a lumen through whichthe actuation element extends along the surgical instrument shaft. Themethod further comprises longitudinally compressing the actuationelement guide between a first block and a second block of the surgicalinstrument into a pre-compressed state along at least a portion of anaxial length of the shaft, according to an exemplary embodiment.According to an exemplary embodiment, the method further comprisesconnecting a flush tube to the first block so the first block is in flowcommunication with the flush tube, the flush tube being configured toreceive a cleaning fluid to direct the cleaning fluid into the lumen ofthe actuation element guide.

Additional objects, features, and/or advantages will be set forth inpart in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the present disclosureand/or claims. At least some of these objects and advantages may berealized and attained by the elements and combinations particularlypointed out in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the claims; rather the claims should beentitled to their full breadth of scope, including equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be understood from the following detaileddescription, either alone or together with the accompanying drawings.The drawings are included to provide a further understanding of thepresent disclosure, and are incorporated in and constitute a part ofthis specification. The drawings illustrate one or more exemplaryembodiments of the present teachings and together with the descriptionserve to explain certain principles and operation.

FIG. 1 shows a perspective view of a patient side cart of a teleoperatedsurgical system, according to an exemplary embodiment.

FIG. 2 is a top schematic view of an exemplary embodiment of a surgicalinstrument including a force transmission mechanism.

FIG. 3 is a side schematic view of surgical instrument mounted to apatient side cart and inserted into a cannula with a curved section,according to an exemplary embodiment.

FIG. 4 is a longitudinal cross-sectional view of a shaft for a surgicalinstrument, with components disposed internal to the shaft being shown,according to an exemplary embodiment.

FIG. 5 is a transverse cross-sectional view of a surgical instrumentshaft with a sheath, according to an exemplary embodiment.

FIG. 6 is a transverse cross-sectional view of a surgical instrumentshaft, according to an exemplary embodiment.

FIG. 7 is a perspective, isolated view of a wrist and actuation elementsfor a surgical instrument, according to an exemplary embodiment.

FIG. 8 is a perspective, isolated view of a wrist and actuation elementsfor a surgical instrument, according to another exemplary embodiment.

FIG. 9 is a perspective view of a tube bundle for a surgical instrument,according to an exemplary embodiment.

FIG. 10 is a schematic cross-sectional view of an instrument shaftincluding actuation element guides, according to an exemplaryembodiment.

FIG. 11 is a perspective view of internal components of a forcetransmission mechanism including a mounted block to hold actuationelement guides, according to an exemplary embodiment.

FIG. 12 is a cross-sectional view of a mount and block for actuationelement guides, according to an exemplary embodiment.

FIG. 13 is a side perspective view of a structure to set and/or adjustthe compression of actuation element guides, according to an exemplaryembodiment.

FIG. 14 is a side view of a structure to set and/or adjust thecompression of actuation element guides, according to another exemplaryembodiment.

FIG. 15 is a perspective view of a structure to set and/or adjust thecompression of actuation element guides, according to another exemplaryembodiment.

FIG. 16 is a perspective view of a block and mount to set and/or adjustthe compression of actuation element guides, according to an exemplaryembodiment.

FIG. 17 is a perspective view of a block and mount to set and/or adjustthe compression of actuation element guides, according to anotherexemplary embodiment.

FIG. 18 is a perspective view of a block, flush tube, and flush platefor a surgical instrument, according to another exemplary embodiment.

FIG. 19 is a cross-sectional view of cleaning passages within a shaft ofa surgical instrument, according to another exemplary embodiment.

FIG. 20 is a cross-sectional view of a compression block includingseals, according to another exemplary embodiment.

FIG. 21 is a side partial sectional view of a proximal portion of aninstrument shaft, according to an exemplary embodiment.

FIG. 22 is a side sectional view of the instrument shaft portion of FIG.21.

FIG. 23 is an exploded view of the instrument shaft portion of FIG. 21.

FIG. 24 is a side partial sectional view of a proximal portion of aninstrument shaft, according to another exemplary embodiment.

FIG. 25 is a side partial sectional view of a proximal portion of aninstrument shaft, according to another exemplary embodiment.

FIG. 26 is a side view of an actuation element guide bundle, accordingto another exemplary embodiment.

DETAILED DESCRIPTION

This description and the accompanying drawings that illustrate exemplaryembodiments should not be taken as limiting. Various mechanical,compositional, structural, electrical, and operational changes may bemade without departing from the scope of this description and claims,including equivalents. In some instances, well-known structures andtechniques have not been shown or described in detail so as not toobscure the disclosure. Like numbers in two or more figures representthe same or similar elements. Furthermore, elements and their associatedfeatures that are described in detail with reference to one embodimentmay, whenever practical, be included in other embodiments in which theyare not specifically shown or described. For example, if an element isdescribed in detail with reference to one embodiment and is notdescribed with reference to a second embodiment, the element maynevertheless be claimed as included in the second embodiment.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages, orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about,” to the extent they are not already so modified.Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” and any singular use of anyword, include plural referents unless expressly and unequivocallylimited to one referent. As used herein, the term “include” and itsgrammatical variants are intended to be non-limiting, such thatrecitation of items in a list is not to the exclusion of other likeitems that can be substituted or added to the listed items.

Further, this description's terminology is not intended to limit thedisclosure or claims. For example, spatially relative terms—such as“beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, andthe like—may be used to describe one element's or feature's relationshipto another element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positions(i.e., locations) and orientations (i.e., rotational placements) of adevice in use or operation in addition to the position and orientationshown in the figures. For example, if a device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be “above” or “over” the other elements or features.Thus, the exemplary term “below” can encompass both positions andorientations of above and below. A device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

In this description, an actively flexible piece may be bent by usingforces inherently associated with the piece itself. For example, one ormore actuation elements (e.g., tendons) may be routed lengthwise alongthe piece and offset from the piece's longitudinal axis, so that tensionon the one or more tendons causes the piece to bend. Other ways ofactively bending an actively flexible piece include, without limitation,the use of pneumatic or hydraulic power, gears, electroactive polymers,and the like. A passively flexible piece is bent by using a forceexternal to the piece. An example of a passively flexible piece withinherent stiffness is a plastic rod or a resilient rubber tube. Anactively flexible piece, when not actuated by its inherently associatedforces, may be passively flexible. A single component may be made of oneor more actively and passively flexible portions in series.

In accordance with various exemplary embodiments, the present disclosurecontemplates surgical instruments that include actuation element guidesconfigured to compensate for changes in length of actuation elementsextending through the actuation element guides. As a result, theactuation element guides may minimize or prevent changes in length inactuation elements, which could otherwise interfere with the functioningof the actuation elements to actuate an instrument, such as, forexample, to actuate an end effector and/or wrist of an instrument. Inaccordance with various exemplary embodiments, at least a portion of anactuation element guide may be compressed into a pre-compressed state.For example, at least a portion of an actuation element guide may becompressed between a first block and a second block. An actuationelement guide in a pre-compressed state may have an excess amount oflength compared to an actuation element guide following straight path.The present disclosure also contemplates the use of devices to setand/or adjust the compression of the actuation element guide. Variousexemplary embodiments further contemplate structures to facilitatereprocessing of instruments that include actuation element guides,including structures that permit flushing of the interior of actuationguide elements.

Referring now to FIG. 1, an exemplary embodiment of a patient side cart100 of a teleoperated surgical system is shown. A teleoperated surgicalsystem may further include a surgeon console (not shown) for receivinginput from a user to control instruments mounted at patient side cart100. A teleoperated surgical system also can include an auxiliarycontrol/vision cart (not shown), as described in, for example, U.S. Pub.No. US 2013/0325033, entitled “Multi-Port Surgical Robotic SystemArchitecture” and published on Dec. 5, 2013, and U.S. Pub. No. US2013/0325031, entitled “Redundant Axis and Degree of Freedom forHardware-Constrained Remote Center Robotic Manipulator” and published onDec. 5, 2013, each of which is hereby incorporated by reference in itsentirety. Further, the exemplary embodiments described herein may beused, for example, with a da Vinci® Surgical System, da Vinci® SiSurgical System, Single Site da Vinci® Surgical System, or a da Vinci®Xi Surgical System, available from Intuitive Surgical, Inc.

Patient side cart 100 includes a base 102, a main column 104, and a mainboom 106 connected to main column 104. A plurality of manipulator arms110, 111, 112, 113 extend from the main boom 106. Manipulator arms 110,111, 112, 113 may each include an instrument mount portion 120 to whichan instrument 130 can be mounted, as illustrated at manipulator arm 110.Manipulator arms 110, 111, 112, 113 can be manipulated during a surgicalprocedure according to commands provided by a user at the surgeonconsole. Signal(s) or input(s) can be transmitted from the surgeon tothe control/vision cart, which interprets the input(s) and generatecommand(s) or output(s) that are transmitted to the patient side cart100. Through drive interface devices and ultimately to the surgicalinstrument transmission mechanism, an instrument 130 (only one suchinstrument being mounted in FIG. 1) can be manipulated by the commands.

Instrument mount portion 120 includes an actuation interface assembly122 and a cannula mount 124. A shaft 132 of instrument 130 extendsthrough a cannula (not shown in FIG. 1) held by cannula mount 124 (andon to a remote site during a surgical or diagnostic procedure), and aforce transmission mechanism 134 of instrument 130 connects with theactuation interface assembly 122. Actuation interface assembly 122includes a variety of drives and other mechanisms that are controlled torespond to input commands at the surgeon console and output drive forces(it should be understood that torque is included in references toforces) to the force transmission mechanism 134 to actuate instrument130, as those skilled in the art are familiar with. For instance, theinput drives of actuation interface assembly 122 can directly engage, orcan engage through a sterile interface adapter, with interfacestructures (not shown) of force transmission mechanism 134 and transmitforces to force transmission mechanism 134 that ultimate actuate thesurgical instrument.

Although the exemplary embodiment of FIG. 1 shows an instrument 130attached to only manipulator arm 110 for ease of illustration, aninstrument may be attached to any and each of manipulator arms 110, 111,112, 113. An instrument 130 may be a surgical instrument with an endeffector or may be an endoscopic imaging instrument or other sensinginstrument utilized during a surgical procedure to provide information,(e.g., visualization, electrophysiological activity, pressure, fluidflow, and/or other sensed data) of a remote surgical site. Those ofordinary skill in the art will appreciate that the embodiments describedherein are not limited to the exemplary embodiment of the patient sidecart of FIG. 1 and various other teleoperated surgical systemconfigurations, including patient side cart configurations, may be used.

FIG. 2 depicts a top view of an exemplary embodiment of a surgicalinstrument 200 for a teleoperated surgical system. For example, surgicalinstrument 130 of FIG. 1 may be configured according to the exemplaryembodiment of FIG. 2. Surgical instrument 200 includes a forcetransmission mechanism 210, a shaft 222 connected to force transmissionmechanism 210 at a proximal end 223 of shaft 222, and an effector 220 ata distal end of the shaft 222, with relative proximal and distaldirections of the surgical instrument being identified in FIG. 2.Instrument 200 also can include a wrist 230 connected to support the endeffector 220 at a distal end of shaft 222, although instrument 200 mayinstead be a non-wristed instrument that lacks a wrist 230. Shaft 222may be flexible or rigid. Shaft 222 can be sized for minimally invasivesurgical procedures. For example, the diameter of shaft 22 can rangefrom about 3 mm to about 15 mm, for example, from about 5 mm to about 8mm.

Surgical instrument 200 further includes one or more members totranslate force between force transmission mechanism 210 and the endeffector 220, and to the wrist 230 if any. For instance, one or moreactuation element(s) 226 extend from force transmission mechanism 210,through the shaft 222, to end effector 220 to transmit actuation forces.End effector 220 can have a variety of configurations, such as, forexample, forceps, a needle driver for suturing, cutting devices,dissecting devices, electrocautery devices, ultrasonic tools, clipappliers, and other end effector configurations for performing varioussurgical procedures as those having ordinary skill in the art arefamiliar with. Actuation element(s) 226 may be in the form of tensionmembers, such as when force transmission mechanism 210 is a pull-pullmechanism, or one or more rods, such as when force transmissionmechanism 210 is a push-pull mechanism, as described in U.S. Pat. No.8,545,515, which is hereby incorporated by reference in its entirety.

Force transmission mechanism 210 may include one or more components toengage with a patient side cart of a teleoperated surgical system totransmit a force provided by the patient side cart to surgicalinstrument 200. According to an exemplary embodiment, force transmissionmechanism 210 may include one or more actuation input mechanisms 212,214 that engage with a manipulator of a patient side cart, such asactuation interface assembly 122 of patient side cart 100, as discussedabove in regard to the exemplary embodiment of FIG. 1.

Turning to FIG. 3, a side view is shown of a cannula 320 coupled to amanipulator arm 310 of a patient side cart, such as one of manipulatorarms 110-113 of the patient side cart 100 of the exemplary embodiment ofFIG. 1. Cannula 320 may be connected to a spar 312 of manipulator arm310 (e.g., via cannula mount 124 in the exemplary embodiment of FIG. 1).An instrument 330 may be coupled to a carriage 314 of spar 312. Carriage314 can include an actuation interface assembly (not shown) to couplewith a force transmission mechanism (not shown) of instrument 330 (e.g.,by coupling force transmission mechanism 134 to actuation interfaceassembly 122 of the exemplary embodiment of FIG. 1.). Carriage 314 maybe configured to move linearly along spar 312 in the direction indicatedby arrows 316 in FIG. 3, which causes the surgical instrument 330 to beinserted and withdrawn through cannula 320. Although cannula 320 isdepicted as being connected to carriage 314 and spar 312 of manipulatorarm 310, the various exemplary embodiments described herein are notlimited to teleoperated surgical instruments and may also regard manual(e.g., hand operated) surgical instruments and curved cannulas notmounted to a teleoperated surgical system.

Teleoperated actuation forces (it should be understood that torque isincluded in references to forces) from various motors 342 mayrespectively control a degree of freedom (DOF) of instrument 330 andkeep a remote center of motion 340 stationary with regard to a referenceframe, such as a body wall of a patient so trauma to tissue isminimized. Although three motors 342 are shown in the exemplaryembodiment of FIG. 3, manipulator arm 310 may include other numbers ofmotors 342. Teleoperated control of manipulator arm 310 is conducted viaa master control unit 350, schematically depicted in the exemplaryembodiment of FIG. 3, which may be a surgeon's console of a teleoperatedsurgical system. Master control unit 350 may include a master input 352that receives an operator's input to control associated slavemanipulator arm 310 and its instrument 330. Master control unit 350includes a memory 354 that includes non-transitory instructions that areexecuted by processing/control system 356 (i.e., that contains a logicunit, such as an adder) to control motion of manipulator arm 310 and itsassociated instrument 330.

Cannula 320 may include a curved section 322. In other words, at least asection of the cannula 320 may have a curved longitudinal axis. Curvedsection 322 may have a curvature with an angle 323 between ends ofsection 322 ranging from, for example, about 40.degree. to about65.degree. In another example, curved section 322 may have a curvatureranging from about 45.degree. to about 60.degree. When two or morecurved cannulas, such as cannulas 320 and 324 in the exemplaryembodiment of FIG. 3, are positioned so the curved sections of thecannulas are generally offset from each other, triangulation (e.g., theability for the distal ends of two surgical instruments to be positionedalong two legs of a triangle to work effectively at a surgical sitelocated at the apex of the triangle) of the cannulas and instruments canbe achieved. Cannula 324 is partially depicted in the exemplaryembodiment of FIG. 3 without attachment to a manipulator arm but,similarly to cannula 320, attaches to a different manipulator arm thanarm 310. Further, using cannulas with curved sections facilitatesinsertion of the cannulas through a single aperture (e.g., incision,port, natural orifice, or other aperture) in a patient's body. Arrangingcannulas 320, 324 in a triangulation configuration facilitates viewing asurgical site and utilizing instruments 330, 332 at the surgical site.

As discussed above, a shaft of a surgical instrument (e.g., shaft 222 ofthe exemplary embodiment of FIG. 2) can be flexible, such as tofacilitate insertion and withdrawal of an instrument through a curvedsection of a cannula. The instrument shaft also has a degree ofstiffness so the shaft may support an end effector, such as when thedistal end of the shaft and the end effector are extended beyond adistal end of the curved cannula. General examples of passively flexibleinstruments are described in U.S. Pat. No. 8,545,515 (entitled “CurvedCannula Surgical System”), issued Oct. 1, 2013, and U.S. ProvisionalPatent Application No. 61/866,367 (entitled “Instrument Shaft forComputer-Assisted Surgical System”), filed Aug. 15, 2013, each of whichis hereby incorporated by reference herein in its entirety. When theflexible shaft of an instrument is inserted and withdrawn through thecurved section of a cannula, the shaft and components within the shaft,such as actuation elements, are bent. Bending may have an effect uponthe actuation elements. For instance, bending may cause a change inlength of an actuation element, depending upon whether the actuationelement is located on an inside of a curve of bending (which could leadto a negative change in length of the actuation element) or on anoutside of the curve of bending (which could lead to a positive changein length of the actuation element).

Actuation Element Guides for Actuation Elements of Surgical Instruments

Various exemplary embodiments described herein contemplate guides foractuation elements of a surgical instrument. Actuation element guides ofthe various exemplary embodiments described herein may direct actuationelements along a length of a surgical instrument. For example, actuationelement guides may provide pathways for actuation elements guidesthrough a shaft of a surgical instrument. The actuation element guidesmay also provide a degree of support for actuation elements, such as byincreasing a buckling strength of the actuation elements. Variousexemplary embodiments described herein contemplate actuation elementguides that have a non-linear shape along at least a portion of itslength when a shaft including the actuation element guides is straight.By using actuation element guides having a non-linear shape, accordingto the various exemplary embodiments described herein, changes in lengthof an actuation element extending through the guide, which may resultfrom bending an instrument shaft including the guide through a curvedsection of a cannula, may be accommodated.

Turning to FIG. 4, a cross-sectional view is shown of a shaft 400 of asurgical instrument, according to an exemplary embodiment. Shaft 400 mayhave a proximal portion 412 and a distal portion 414, and include one ormore actuation element guides 420, 422, 424 that extend between proximalportion 412 and distal portion 414 of shaft 400. As shown in theexemplary embodiment of FIG. 4, actuation element guide 422 may be heldbetween a proximal block 430 disposed at proximal portion 412 of shaft400 and a distal block 432 disposed at distal portion 414 of shaft 400.According to an exemplary embodiment, proximal block 430 may be fixed toa force transmission mechanism (e.g., force transmission mechanism 210of FIG. 2), as will be discussed below. Other actuation element guides,such as actuation element guides 420 and 424, also may be held betweenblocks 430 and 432.

As mentioned above, instrument shaft 400 may have a rolling degree offreedom, such that shaft 400 is able to rotate about its longitudinalaxis. According to an exemplary embodiment, shaft 400 may include gearteeth 416 to mesh with a roll input gear (not shown) or other mechanismof a force transmission mechanism (e.g., force transmission mechanism210 of FIG. 2) to induce a rolling motion for shaft 400, such as to rollshaft 400 along the directions indicated by arrows 452 aboutlongitudinal axis 450 in the exemplary embodiment of FIG. 4. Distalblock 432 is connected to a distal portion 414 of shaft 400 in a fixedmanner so that distal block 432 rolls as shaft 400 is rolled. As shown,actuation element guides 420, 422, 424 are fixed to distal block 432 andto proximal block 430 so as to compress actuation element guides 420,422, 424 into a pre-compressed state between proximal block 430 anddistal block 432. As a result, actuation element guides 420, 422, 424roll when shaft 400 is rolled. Actuation element guides 420, 422, 424can roll together as a single unit with shaft 400, or alternatively, oneor more actuation element guides 420, 422, 424 can roll independently ofone another.

According to an exemplary embodiment, actuation element guides 420, 422,424 are configured to rotate relative to at least one of blocks 430,432. For example, proximal block 430 may be fixed to a forcetransmission mechanism of an instrument (e.g., fixed to forcetransmission mechanism 210 of the exemplary embodiment of FIG. 2) whileshaft 400, distal block 432, and actuation element guides 420, 422, 424are rotatable (e.g., roll) about axis 450 relative to the forcetransmission mechanism. As a result, actuation element guides 420, 422,424 are held by proximal block 430 while also being rotatable relativeto proximal block 430. In some cases, rotation of the actuation elementguides 420, 422, 424 relative to fixed proximal block 430 results intwisting of at least a portion of actuation element guides 420, 422,424.

Proximal block 430 may be made of a material to minimize wear due to therotational motion between actuation element guides 420, 422, 424 andproximal block 430. For example, proximal block 430 may be made of ananti-galling material, such as, for example, Nitronic® 60 alloy, whichis distributed by High Performance Alloys. According to an exemplaryembodiment, either or both of blocks 430, 432 may be made of, forexample, a plastic material, a metal, a combination of a plasticmaterial and a metal, or other surgical instrument materials familiar toone of ordinary skill in the art. For example, block 430 and/or block432 may be made of polyether ether ketone (PEEK).

The present disclosure contemplates configurations other than thosedescribed above for FIG. 4. For example, actuation element guides 420,422, 424 may be rotatable relative to both distal block 432 and proximalblock 430. As a result, when shaft 400 and proximal block 430 arerolled, actuation element guides 420, 422, 424 remain stationaryrelative to shaft 400 and block 430. In another exemplary embodiment,actuation element guides 420, 422, 424 are compressed between proximaland distal blocks 430, 432, but actuation element guides 420, 422, 424also pass through proximal block 430 into a force transmission mechanism(e.g., force transmission mechanism 210 of FIG. 2) where actuationelement guides 420, 422, 424 are fixed. Further, distal block 432 may berotatable relative to actuation element guides 420, 422, 424 sinceactuation element guides 420, 422, 424 are fixed to the forcetransmission mechanism.

Shaft 400 may be a flexible hollow body 418 through which actuationelement guides 420, 422, 424 extend. According to an exemplaryembodiment, hollow body 418 may define an inner wall 417. The portion ofhollow body 418 defining inner wall 417 may be a continuous surfacealong the axial length of shaft 400 (e.g., along the proximal-distaldirection of shaft 400). An open space 419 is provided between innerwall 417 of hollow body 418 and actuation element guides 420, 422, 424,so as to provide space for other instrument components that extendthrough shaft 400 (e.g., one or more flux conduits to convey, forexample, electrical energy, fluid, suction, and other fluxes used bysurgical instruments). Actuation element guides (e.g., actuation guideelements 420, 422, 424) held between proximal block 430 and distal block432 may be unconstrained (e.g., not in contact with support structuresto direct or support guides) between those blocks. For instance, openspace 419 may be located between actuation element guides 420, 422, 424and between guides 420, 422, 424 and inner wall 417 of hollow body 418.The open space 419 within hollow body 418 provides an unconstrainedconfiguration for actuation element guides 420, 422, 424, which permitsactuation element guides 420, 422, 424 to move freely within hollow body418. Such a configuration can facilitate compensating for changes in thelength of guides 420, 422, 424, as will be discussed in further detailbelow.

According to an exemplary embodiment, actuation elements may beprimarily supported along shaft 400 by actuation element guides 420,422, 424 instead of hollow body 418 due to the limited contact betweenhollow body 418 and actuation element guides 420, 422, 424. This isfurther illustrated in the exemplary embodiment of FIG. 5, which is across-sectional view of a surgical instrument shaft 500, which may be across-section located along line 440-440 of FIG. 4. As shown in theexemplary embodiment of FIG. 5, shaft 500 may comprise a hollow body 510through which actuation element guides 520-525 may extend, withactuation elements 530-535 (e.g., pull/pull tension elements)respectively extending through an interior of actuation element guides520-525. Hollow body 510 and actuation element guides 520-525 may beconfigured so that open space 514 is provided between an interior wall511 of hollow body 510 and actuation element guides 520-525, asdescribed above.

A surgical instrument shaft can be made of materials that provide theshaft with flexibility, such as to facilitate bending of the shaft wheninserting and withdrawing the shaft, for example, through a curvedsection of a cannula. However, a surgical instrument shaft also can bemade of materials that provide the shaft with sufficient stiffness, forexample, to support an end effector of the surgical instrument when adistal portion of the instrument including the end effector is extendedbeyond a distal end of a cannula. For example, hollow body 510 may bemade of PEEK, according to an exemplary embodiment. The PEEK may includeone or more fillers, such as, for example, glass fiber reinforcement orcarbon fiber reinforcement. According to an embodiment, a material usedfor a shaft may include a material to increase the lubricity of theshaft. For instance, the material of the shaft may include, for example,about 5% to about 10% of PTFE and/or perfluoropolyether (PFPE).

A surgical instrument shaft also can include additional layers and/ormaterials. For example, shaft 500 may further include an outer layer 512(e.g., a sheath), as shown in the exemplary embodiment of FIG. 5. Outerlayer 512 may comprise, for example, a lubricious material to facilitateinsertion and withdrawal of shaft 500 through a cannula. Outer layer 512may comprise, for example, ethylene tetrafluoroethylene (ETFE) or othershaft materials familiar to one of ordinary skill in the art. The outerlayer 512 of ETFE may be, for example, heat shrunk onto hollow body 510.However, a shaft 600 of a surgical instrument may include only a hollowbody 610 without additional layers, as shown in the exemplary embodimentof FIG. 6, which also depicts actuation element guides 620-625 andactuation elements 630-635 extending through hollow body 610. Hollowbody 610 may be made of, for example, PEEK, PEEK comprising one or morefiller, or other shaft materials familiar to one of ordinary skill inthe art.

With reference to the exemplary embodiments of FIGS. 5 and 6, thesurgical instrument includes six actuation element guides 520-525,620-625 for receiving six actuation elements 530-535, 630-635. The sixactuation elements 530-535, 630-635 may be used to actuate, for example,an end effector (such as end effector 220 of the exemplary embodiment ofFIG. 2) and a wrist (such as wrist 230 of the exemplary embodiment ofFIG. 2). According to an exemplary embodiment, two of actuation elements530-535, 630-635 can actuate an end effector, such as when actuationelements 530-535, 630-635 are pull/pull type tension elements. Further,four of actuation elements 530-535, 630-635 can actuate a wrist. Ofcourse those having ordinary skill in the art would appreciate thatother numbers and arrangements of actuation elements may be providedwithout departing from the scope of the present disclosure.

Turning to FIG. 7, an exemplary embodiment of a wrist 700 is shown thatmay be used with the various exemplary embodiments described herein.Wrist 700 includes a series of links 702-705 coupled to one another toprovide joints 710 and 712 that permit wrist 700 to bend in pitch andyaw directions when actuation elements 730-733 are tensioned to actuatewrist 700. The pitch and yaw directions may be arbitrary rotationalmotions about orthogonal axes in a Cartesian reference system. Thus,wrist 700 may be a two stage (AB) wrist with two physical pivots atjoints 710 and 712, so there are two DOFs for wrist 700, namely a pitchDOF (A) and a yaw DOF(B). Wrist 700 can have, for example, a range ofmotion of about +/−45 degrees for each joint 710, 712, according to anexemplary embodiment. By using a wrist with few joints, such as wrist700, a relatively small number of actuation elements, such as fouractuation elements 730-733 in the exemplary embodiment shown, may beused. As a result, additional free space may be used within a surgicalinstrument shaft for other instrument components, including, forexample, actuation element guides that may be permitted to move withinthe open space of a hollow body of the shaft.

Although a wrist with 2 DOFs may be used, such as wrist 700, other wristconfigurations may be used with the various exemplary embodimentsdescribed herein. For example, wrist 800 of the exemplary embodiment ofFIG. 8 may be used. Wrist 800 comprises disks 801-808 coupled to oneanother to provide four joints 810, 812, 814, 816. Adjacent links ofwrist 800 may pivot about joints 810, 812, 814, 816 when actuationelements 830 are tensioned so as to bend wrist 800 about arbitrary pitchand yaw directions. Thus, wrist 800 may be a four stage wrist (e.g.,ABBA type wrist or other combinations of pitch and yaw) with 4 DOFs.Wrist 800 may have a greater range of motion than wrist 700 but requirea larger number of actuation elements 830 (e.g., eight actuationelements 830) to actuate and bend wrist 800 via joints 810, 812, 814,816. According to an exemplary embodiment, wrist 800 may be used andconfigured according to the various exemplary embodiments described inU.S. Pub. No. US 2012/0215220 (entitled “Fusing and Cutting SurgicalInstrument and Related Methods”), published on Aug. 23, 2012, which ishereby incorporated by reference in its entirety. According to anexemplary embodiment, wrist 800 has a range of motion of about +/−80degrees to about +/−90 degrees for each degree of freedom of wrist 800.In general, increasing the number of actuation elements leads to morespace being taken up within the instrument shaft due to the spacerequired for increasing the number of actuation elements.

The various exemplary embodiments described herein also can includewrist configurations as described in U.S. Pat. No. 6,817,974, entitled“Surgical Tool Having Positively Positionable Tendon-Actuated Multi-DiskWrist Joint” and issued on Nov. 16, 2004, and U.S. Pat. No. 7,320,700,entitled “Flexible Wrist for Surgical Tool” and issued on Jan. 22, 2008,each of which is incorporated by reference herein in its entirety.

Actuation elements of the various exemplary embodiments described hereinmay extend along a 180 degree turn at a distal end of a wrist. Forexample, actuation element 730 of the exemplary embodiment of FIG. 7 mayfollow a 180 degree turn at distal end 714 of wrist 700 and extend backalong wrist as actuation element 731. In another example, each of theactuation elements may terminate at a distal end of wrist and be coupledto the distal end of the wrist. For example, each of actuation elements730-733 may terminate at distal end 714 of wrist 700 and be coupled todistal end 714, such as via crimps (not shown).

Actuation element guides may be structures to support and guideactuation elements along a desired path through a shaft of a surgicalinstrument. According to an exemplary embodiment, actuation elementguides may be hollow tubes, such as actuation element guides 520-525,620-625 in the exemplary embodiments of FIGS. 5 and 6. The hollow tubesmay be made of a material that permits the hollow tubes to be flexibleand bend, but also that provides a degree of stiffness so as to supportactuation elements extending through the interior of the hollow tubes.According to an exemplary embodiment, the hollow tubes may be made ofstainless steel or other surgical instrument material. For example,suitable materials include, but are not limited to, type 304 stainlesssteel, 17-7 stainless steel, and/or type 316 stainless steel, or otherstainless steel alloys familiar to one of ordinary skill in the art.According to another exemplary embodiment, the hollow tubes may be madeof a nickel-titanium alloy (e.g., a Nitinol alloy), or a polymer, suchas, for example PEEK or other polymers familiar to one of ordinary skillin the art.

Turning to FIG. 9, a bundle 900 of actuation element guides is shownextending between a proximal block 902 and a distal block 904. Actuationelement guides of various exemplary embodiments described herein, suchas actuation element guides 420, 422, 424 of FIG. 4, may be configuredaccording to the hollow tubes of bundle 900 of the exemplary embodimentof FIG. 9. The hollow tubes of bundle 900 may have solid walls definingcontinuous inner surfaces along their axial length (e.g., betweenproximal block 902 and distal block 904), according to an exemplaryembodiment. According to an exemplary embodiment, the hollow tubes ofbundle 900 may be unconstrained (e.g., not in contact with supportstructures to direct or support guides) between proximal block 902 anddistal block 904, as discussed above with regard to the exemplaryembodiment of FIG. 4.

Although only four hollow tubes 910-913 are visible in the exemplaryembodiment of FIG. 9, bundle 900 may include various numbers of hollowtubes. For instance, bundle 900 may include six hollow tubes (two ofwhich are hidden from view in FIG. 9), with apertures 920-925 for theends of the hollow tubes located in proximal block 902 to receiveactuation elements (not shown) to extend through the hollow tubes.However, bundle 900 may comprise other numbers of hollow tubes, such as,for example, one, two, three, four, five, seven, eight, nine, ten, ormore hollow tubes.

According to an exemplary embodiment, proximal block 902 includes anaperture 906 to receive cleaning fluid that is distributed to thevarious hollow tubes for cleaning purposes, as will be described below.Distal block 904 includes a corresponding number of apertures (notshown) for the hollow tubes as proximal block 902. Hollow tube bundle900 may be used in the various exemplary embodiments described herein,such as by extending the hollow tubes of bundle 900 between proximalblock 430 and distal block 432 of the exemplary embodiment of FIG. 4(e.g., bundle 900 can include actuation element guides 420, 422, 424 ofFIG. 4).

As discussed above, bending a shaft of a surgical instrument, such aswhen a surgical instrument extends through a curved section of acannula, may result in a change of length of actuation elementsextending through the shaft. To compensate for such changes in length,actuation element guides may have a non-linear shape, when a shaftincluding the actuation element guides is straight (e.g., before theshaft is bent and/or actuation forces are applied to actuationelements), along at least a portion of the length of the actuationelement guides. According to an exemplary embodiment, an actuationelement guide may be pre-compressed (e.g., in a pre-compressed state,such as, for example, before the shaft including the actuation elementguide is bent and/or actuation forces are applied to actuation elements)to accomplish a non-linear shape along at least a portion of the lengthof the actuation element guide when a shaft including the actuationelement guides is straight. For example, actuation element guides 420,422, 424 in the exemplary embodiment of FIG. 4 may be coupled toproximal block 430 and distal block 432 such that actuation elementguides 420, 422, 424 are pre-compressed between block 430 and block 432.According to an exemplary embodiment, the pre-compression force on theactuation element guides 420, 422, 424 can range, for example, fromabout 1 pound (lbf) to about 15 pounds (lbf), for example thepre-compression force may range from about 1 pound (lbf) to about 10pounds (lbf). In another example, tubes 910-913 in the exemplaryembodiment of FIG. 9, which may function as actuation element guides,can be coupled to proximal block 902 and distal block 904 such thattubes 910-913 are pre-compressed between proximal block 902 and distalblock 904.

Turning to FIG. 10, an instrument shaft 1000 is schematically shown in abent configuration to demonstrate how actuation element guides of thevarious exemplary embodiments described herein function to compensatefor changes in length of actuation elements. For example, the actuationelement guides of FIGS. 4 and 9 and the following embodiments describedbelow may be configured according to the exemplary embodiment of FIG. 10(e.g., the exemplary embodiments described herein may be bent into theconfiguration shown in FIG. 10 and function in the same manner). Shaft1000 may be a flexible shaft, such as, for example, shaft 400 of theexemplary embodiment of FIG. 4, which has been bent, such as byextending shaft 1000 through a curved portion of a cannula (e.g.,through curved portion 322 of cannula 320 in the exemplary embodiment ofFIG. 3). Actuation element guides 1020, 1022 extend through an interiorof shaft 1000, with actuation elements 1030, 1032 respectfully extendingthrough guides 1020, 1022. Actuation element guides 1020, 1022 may beconfigured according to the various exemplary embodiments describedherein, such as, for example, guides 420, 422, 424 in FIG. 4 or bundle900 in FIG. 9.

As depicted in the exemplary embodiment of FIG. 10, actuation elementguides 1020, 1022 can have a non-linear shapes along at least a portionof the lengths of actuation element guides 1020, 1022 (e.g., along alongitudinal axis of actuation element guides 1020, 1022). For example,actuation element guides 1020, 1022 have non-linear shapes when shaft1000 is straight. In this way, when shaft 1000 is straight, actuationelement guides 1020, 1022 have excess length (e.g., relative to a guidefollowing a straight path from one end of shaft 1000 to the other) sothat guides 1020, 1022 are not straight (e.g., non-linear) along atleast a portion of the lengths of guides 1020, 1022. In other words,actuation element guides 1020, 1022 extend along a path that deviatesfrom a straight path between first and second blocks. To provideactuation element guides 1020, 1022 with non-linear shapes, actuationelement guides 1020, 1022 are pre-compressed between blocks (not shown)at opposite ends of actuation element guides 1020, 1022, as discussedabove with regard to the exemplary embodiments of FIGS. 4 and 9.

The shafts and actuation element guides of the various exemplaryembodiments described herein may be designed to compensate for changesin length of actuation elements, such as, for example, changes in lengthdue to bending, rolling and/or twisting motions of actuation elementguides. By compensating for changes in length of actuation elements, thevarious exemplary embodiments described herein may minimize or preventchange in length of the actuation elements, which could otherwisedegrade the efficacy of actuation elements to actuate a surgicalinstrument. For instance, because actuation element guides 1020, 1022are pre-compressed, actuation element guides 1020, 1022 have excesslength relative to a longitudinal axis 1012 of shaft 1000 when shaft1000 is straight, such as, for example, when shaft 1000 does not extendthrough a curved portion of a cannula. According to an exemplaryembodiment, actuation element guides 1020, 1022 are pre-compressed by anamount so that even under a maximum amount of bending, such as whenshaft 1000 is inserted through a cannula curved section with thegreatest degree of bending, actuation elements guides 1020, 1022 willremain pre-compressed with an excess amount of length. According to anexemplary embodiment, because actuation elements 1030, 1032 extendthrough and are guided by actuation element guides 1020, 1022, actuationelements 1030, 1032 also have an excess amount of length. Further, shaft1000 may be a hollow shaft that provides open space 1010 within shaft1000, so that actuation element guides 1020, 1022 are unconstrained byshaft 1000 along at least a portion of the length of actuation elementguides 1020, 1022. As a result, actuation element guides 1020, 1022 maymove relative to shaft 1000 and/additional components may extend throughshaft 1000, as discussed above with regard to the exemplary embodimentof FIG. 4.

According to an exemplary embodiment, when actuation elements 1030, 1032experience a negative change in length, such as due to bending of shaft1000 and at least a portion of actuation elements 1030, 1032 beingdisposed on an inside of a curve of bending, the excess length ofactuation element guides 1020, 1022 due to the pre-compressed shapes ofactuation element guides 1020, 1022 compensates for the negative changein length. Thus, when actuation elements 1030, 1032 experience apositive change in length, such as due to bending of shaft 1000 and atleast a portion of actuation elements 1030, 1032 being disposed on anoutside of the curve of bending, actuation elements guides 1020, 1022may be unconstrained within open space 1010 to permit actuation elementguides 1020, 1022 to move relative to shaft 1000. Thus, designingactuation element guides 1020, 1022 to be pre-compressed andunconstrained within open space 1010 of shaft 1000 permits the guides1020, 1022 to move relative to shaft 1000 so that the positive change inlength due to bending may be absorbed and effects of change in lengthupon actuation elements 1030, 1032 may be minimized or avoided.

Various exemplary embodiments herein can compensate for changes inlength of actuation elements at any orientation of an instrumentrelative to a curved portion of a cannula. In other words, a particularinstrument orientation relative to a curved portion of a cannula is notrequired (e.g., angular rotation relative to a longitudinal axis of theinstrument, such as a roll angle relative to a longitudinal axis of aninstrument). For example, when the curvature of curved section 322 ofcannula 320 in the exemplary embodiment of FIG. 3 lies in a singleplane, instruments including actuation element guides according to thevarious exemplary embodiments described herein do not need to beinserted into cannula 320 so the instrument, and an actuation elementguide within the instrument, is oriented at a particular angle relativeto the plane of curvature in order for the actuation element guide to beable to compensate for changes in length of an actuation elementextending within the actuation element guide. Instead, theconfigurations (e.g., excess length of guides and/or open space withinshafts) permit the actuation element guides to compensate for changes inlength of actuation elements at any orientation relative to thecurvature of a cannula.

The present disclosure also contemplates the use of structures to setand/or adjust an amount of compression of actuation element guides so asto achieve the desired precompression. Turning to FIG. 11, an exemplaryembodiment of a proximal portion 1100 of a surgical instrument is shown,which includes a shaft 1120 and a force transmission mechanism 1110.Shaft 1120 and force transmission mechanism 1110 may be configuredaccording to the exemplary embodiments of FIGS. 1-10. For example, forcetransmission mechanism 1110 may include actuation input mechanisms 1130to actuate actuation elements 1132, which are connected to actuationinput mechanisms 1130 and extend through shaft 1120. Actuation inputmechanisms 1130 may be capstans and actuation elements 1132 may be, forexample, cables, although the exemplary embodiments described herein arenot limited to this configuration. Force transmission mechanism 1110 mayfurther include an actuation input mechanism 1124 to engage a roll gear1122 and roll shaft 1120.

Structures to Set and/or Adjust Compression of Actuation Element Guides

As depicted in the exemplary embodiment of FIG. 11, force transmissionmechanism 1110 includes a block 1140 held in a mount 1142. Block 1140may be configured, for example, according to block 430 in the exemplaryembodiment of FIG. 4. For example, an array of actuation element guides1150, which may be configured according to the exemplary embodiments ofFIGS. 4-10, is held by block 1140 and a block (not shown, such as block432 in FIG. 4) at a distal portion of shaft 1120. Block 1140 may be heldin mount 1142 so that an amount of compression exerted upon actuationelement guides 1150 can be set and/or adjusted. Setting and/or adjustingan amount of compression of an actuation element guide can beaccomplished during the assembly and/or reprocessing of an instrument.For example, an amount of compression of an actuation element guide maybe set and/or adjusted during assembly of an instrument, for example tocompensate for length differences due to variation in manufacturingprocesses. The amount of compression of an actuation element guide maybe reset and/or readjusted during reprocessing of the instrument forfurther use.

As shown in the exemplary embodiment of FIG. 12, mount 1142 includes oneor more set screws 1144 that engage a surface 1141 of block 1140. Thecompression of actuation element guides 1152, 1154, 1156 held withinblock 1140 is set by applying a force to block 1140 to compressactuation element guides 1152, 1154, 1156, such as by applying a forceto block 1140 along direction 1145 in the exemplary embodiment of FIG.12, and adjusting set screws 1144 along the directions indicated byarrows 1143 in FIG. 12 until the set screws 1144 engage surface 1141 ofblock 1140 to maintain block 1140 in its position and maintain actuationelement guides 1152, 1154, 1156 in a compressed state. According to anexemplary embodiment, surface 1141 may be sloped to facilitatemaintaining block 1140 in its set position, such as when block 1140 issubjected to loads during use of a surgical instrument including block1140, such as from actuation elements (not shown in FIG. 12) extendingthrough actuation element guides 1152, 1154, 1156 and block 1140.

Actuation element guides 1152, 1154, 1156 may be held by block 1140within individual holes, such as by disposing a proximal end 1151 ofactuation element guide 1152 within hole 1147 of block 1140. Block 1140also includes individual passages, such as passage 1146, to receiveactuation elements (e.g. actuation elements 1132 in FIG. 11) and routethe actuation elements to individual actuation element guides 1152,1154, 1156. Although only three actuation element guides 1152, 1154,1156 are depicted in the exemplary embodiment of FIG. 12, other numbersof actuation element guides and a corresponding number of actuationelements may be utilized, such as, for example, one, two, four, five,seven, eight, nine, ten, or more.

Other structures may be utilized to set and/or adjust an amount ofcompression to achieve the pre-compression of actuation element guides.As depicted in the exemplary embodiment of FIG. 13, an actuation elementguide 1250 extends from an instrument shaft 1220 to a block 1240 locatedwithin a force transmission mechanism of an instrument. Actuationelement guide 1250, shaft 1220, and a proximal block 1240 may bearranged according to the exemplary embodiments of FIGS. 4-10. Asdepicted in the exemplary embodiment of FIG. 13, block 1240 includes oneor more passages 1244 through which one or more actuation element(s)(not shown) respectively extend to one or more actuation elementguide(s) 1250. Block 1240 may be held by a mount 1242, as illustrated inFIG. 13.

A wedge 1260 inserted between a plate 1230 and block 1240, such as alongthe directions indicated by arrows 1266 in FIG. 13, can be used to setand/or adjust an amount of compression exerted by block 1240 uponactuation element guide 1250. Wedge 1260 has an inclined surface 1262that is urged against block 1240 as the wedge 1260 is inserted betweenplate 1230 and block 1240. Because surface 1262 is a continuous linearsurface, wedge 1260 provides a linear, continuously variable ability toadjust and/or set the amount of compression for actuation element guide1250 via moving block 1240 as the position of wedge 1260 is adjustedbetween plate 1230 and block 1240. Surface 1262 may have an inclineranging from about 5 to about 10 degrees, according to an exemplaryembodiment. According to an exemplary embodiment, a hold-down member(not shown) is provided to contact a top surface of wedge 1260 andfacilitate maintaining a position of wedge 1260 between plate 1230 andblock 1240. Suitable hold down members include, but are not limited to,a fastener (e.g., set screw), flexure member, adhesive, weld, deformedmember, or other structures familiar to one of ordinary skill in theart.

Another exemplary embodiment for setting and/or adjusting an amount ofcompression of actuation element guides is depicted in FIG. 14. As shownin FIG. 14, one or more actuation element guide(s) 1350 may extendthrough a shaft 1320 of an instrument to a block 1340 located within aforce transmission mechanism of the instrument. Actuation element guide1350, shaft 1320, and block 1340 may be arranged according to theexemplary embodiments of FIGS. 4-10. Block 1340 may be held within amount 1342, as shown in FIG. 14, and may include one or more passage(s)for actuation element(s) (not shown) to extend through block 1340 torespective one or more actuation element guide(s) 1350. Block 1340includes screw threads 1346 that engage with a threaded nut 1360. Asdepicted in the exemplary embodiment of FIG. 14, nut 1360 engages withmount 1342 so that the position of nut 1360 is fixed along thedirections indicated by arrows 1348 in FIG. 14. As a result, when nut1360 is rotated relative to block 1340 (e.g., to tighten or loosen nut1360), mount 1340 is moved along the directions indicated by arrows1348, which sets and/or adjusts the compression exerted by block 1340upon the one or more actuation element guide(s) 1350.

FIG. 15 depicts yet another exemplary embodiment for setting and/oradjusting an amount of compression of actuation element guides, whichincludes a block 1440 disposed in a force transmission mechanism of aninstrument and held by a mount 1450. Block 1440 may be made of, forexample, a metal, such as a stainless steel alloy, or a polymer (e.g.,an injected molded polymer), according to an exemplary embodiment. Mount1450 may be fixed to a force transmission mechanism (e.g., forcetransmission mechanism 1110 of the exemplary embodiment of FIG. 11) ormount 1450 may be integrally formed as a part of a chassis of a forcetransmission mechanism, according to an exemplary embodiment.

Block 1440 may be arranged according to the exemplary embodiments ofFIGS. 4-10, except that block 1440 includes one or more ratchet teeth1442, as depicted in the exemplary embodiment of FIG. 15. Mount 1450 inturn includes one or more ratchet pawls 1452 that engage the ratchetteeth 1442, according to an exemplary embodiment. For example, block1440 may be moved along the direction indicated by arrow 1460 in FIG. 15to increase the amount of compression applied by block 1440 to one ormore actuation element guide(s) (not shown). As block 1440 is moved,ratchet teeth 1442 slide past ratchet pawl 1452 so that the amount ofcompression applied by block 1440 may be set and/or adjusted. Ratchetteeth 1442 may flex and move toward one another to facilitate movementof ratchet projections 1442 over ratchet portions 1452 as block 1440 ismoved along direction 1460, according to an exemplary embodiment.According to an exemplary embodiment, the distance between consecutiveratchet teeth 1442 along direction 1460 may be varied to provide adesired control for varying the amount of compression applied by block1440.

FIG. 16 depicts another exemplary embodiment for setting and/oradjusting an amount of compression of actuation element guides, whichincludes a block 2040 disposed in a force transmission mechanism of aninstrument and held by a mount 2050. Block 2040 may be arrangedaccording to the exemplary embodiments of FIGS. 4-10. According to anexemplary embodiment, mount 2050 includes a clamp portion 2052 thatapplies pressure to an outer diameter of block 2040 to set thecompression applied by block 2040 to one or more actuation elementguide(s) (not shown), such as by fastening clamp portion 2052 to mount2050 (e.g., via one or more screws 2060). Clamp portion 2052 can bemanufactured as an integral, single piece with mount 2050, with clampportion 2052 having a thickness to facilitate elastic deformation ofclamp portion 2052. For example, clamp portion 2052 may be pivotablymounted relative to mount 2050, such as along directions 2054 in theexemplary embodiment of FIG. 16. Clamp portion 2052 includes a surface2053 having a shape complementary to a shape of block 2040. Mount 2050and clamp portion 2052 can be made of, for example, machined metal(e.g., a stainless steel alloy), a polymer material (e.g., an injectionmolded polymer material), or other material familiar to one of ordinaryskill in the art. According to another exemplary embodiment, clampportion 2052 is provided as a separate piece that is fastened to mount2050, such as via screws.

Other clamping configurations are contemplated by the various exemplaryembodiments described herein for setting and/or adjusting an amount ofcompression of actuation element guides. FIG. 17 depicts anotherexemplary embodiment that includes a block 2140 disposed in a forcetransmission mechanism of an instrument and held by a mount 2150. Block2140 may be arranged according to the exemplary embodiments of FIGS.4-10 except that block 2140 includes a flange portion 2142 to befastened to mount 2150, such as via one or more screws 2160. Flangeportion 2142 includes an elongated aperture 2144, as depicted in theexemplary embodiment of FIG. 17. Elongated aperture 2144 is larger thanscrew 2160, permitting the position of block 2170 to be adjusted alongdirections 2170, while also permitting block 2170 to be fastened tomount 2150 via screw 2160, so that an amount of compression of actuationelement guides (not shown) mounted to block 2140 may be set and/oradjusted.

In another exemplary embodiment for setting and/or adjusting an amountof compression of actuation element guides, a block may include aplurality of concentric tapered fittings that may be adjusted along anaxial length of the block and fixed to one another to set and/or adjustthe compression applied by the block. Other structures for settingand/or adjusting the compression applied by the block to one or moreactuation element guide(s) that may be familiar to one of ordinary skillin the art are contemplated as within the scope of the presentdisclosure.

Reprocessing of Instruments Including Actuation Element Guides

A surgical instrument also may include structures to facilitate cleaningof the surgical instrument, such as a flush tube 1160 depicted in FIGS.11 and 12. Turning to FIG. 18, a block 1540, flush tube 1520, and flushplate 1510 are depicted. These components may be located within a forcetransmission mechanism (not shown) of a surgical instrument. Block 1540may be configured according to the exemplary embodiments of FIGS. 4 and11-15. Flush plate 1510 may form an outer surface of a forcetransmission mechanism so that a fluid source (e.g., a cleaning fluidsource) connected to flush plate 1510 can deliver fluid into thesurgical instrument during a cleaning procedure. For example, flushplate 1510 may include a flush port 1512 fluidically connected to flushtube 1520, which is in turn fluidically connected to block 1542. Asshown in the exemplary embodiment of FIG. 18, a first end 1522 of flushtube 1522 is located within a channel 1514 fluidically connected toflush port 1512, with channel 1514 being sealed with flush tube 1520.For instance, a seal 1530 may be disposed within channel 1514 to sealflush tube 1520 with channel 1514. Flush tube 1520 may be disposedwithin an aperture 1542 of block 1540 to connect flush tube 1520 toblock 1540, as shown in the exemplary embodiment of FIG. 18. Flush tube1520 may be sealed to block 1540, such as via, for example, weldingflush tube 1520 to block 1540.

Fluid delivered to a block, such as via a flush tube, may be distributedamong various actuation element guides coupled to the block so the fluidmay flow through the guides during a cleaning procedure. Asschematically depicted in FIG. 19, a plurality of actuation elementguides 1650 are coupled to a block 1640, which may be fluidicallyconnected to a flush tube 1630, as described above with regard to theexemplary embodiment of FIG. 18, and include one or more passage(s) 1644through which one or more actuation element(s) (not shown) may extend tothe actuation element guides 1650. According to an exemplary embodiment,proximal block 1640 includes a distribution chamber 1642 through whichfluid supplied from flush tube 1630 may be distributed to the variousactuation element guides 1650. As schematically depicted in theexemplary embodiment of FIG. 19, fluid flows through an interior ofactuation element guides 1650 that are disposed within an instrumentshaft 1620 until the fluid reaches the distal ends of the guides 1650,which are coupled to a distal block 1660, as discussed above with regardto the exemplary embodiment of FIG. 4. Fluid exits the actuation elementguides 1650 and distal block 1660 and, due to a shaft seal 1622, isdirected through an interior of shaft 1620 between an inner wall 1624 ofshaft 1620 and guides 1650. For example, shaft 1620 may include an openspace 1624 between inner wall 1624 and guides 1650, as discussed abovewith regard to the exemplary embodiment of FIG. 4, and fluid exiting theguides 1650 is directed through open space 1624 back towards block 1640to facilitate cleaning an interior of shaft and the exterior of guides1650. According to an exemplary embodiment, the fluid exits shaft 1620,such as via one or more aperture(s) (not shown) in shaft 1620 proximateto block 1640.

Blocks of the various exemplary embodiments described herein may includesealing structures to facilitate forming a seal between the block andthe various actuation elements and actuation element guides connected toa block. Turning to FIG. 20, a block 1740 is depicted that includes afirst passage 1742 to receive an actuation element (not shown) and asecond passage 1743 to direct the actuation element into an actuationelement guide (not shown) connected to second passage 1743. To sealblock 1740 to the actuation element and the guide, block 1740 mayinclude a first seal 1744 including a channel 1745 and a second seal1746 including a channel 1748. Although a single passage and channel isdepicted through each of block 1740 and seals 1744, 1746, each of block1740 and seals 1744, 1746 may include a plurality of passages andchannels corresponding to a number of actuation elements of aninstrument, such as, for example, two, three, four, five, six, seven, oreight or more. Seals 1744, 1746 may be made of, for example, anelastomer, such as rubber, or other seal material familiar to one ofordinary skill in the art. According to an exemplary embodiment,passages 1745, 1748 may have a diameter equal to or less than a diameterof an actuation element extending through passages 1745, 1748 tofacilitate sealing with the actuation element. According to an exemplaryembodiment, block 1740 may be disposed within a force transmissionmechanism of a surgical instrument and may include other features, suchas the features of the various exemplary embodiments of FIGS. 4-17described above.

Blocks 1140, 1240, 1340, 1440, 1540, 1640, 1740, 2040, 2140 of theexemplary embodiments of FIGS. 11-20 may be stationary, with actuationelement guides compressed by blocks 1140, 1240, 1340, 1440, 1540, 1640,1740, 2040, 2140 and also rotatable relative to blocks 1140, 1240, 1340,1440, 1540, 1640, 1740, 2040, 2140 such as when a shaft through whichthe actuation element guides extend is rotated. The blocks may furthercontain a manifold to distribute cleaning fluid to various actuationelement guides compressed by the blocks, such as according to theexemplary embodiment of FIG. 19. Thus, blocks 1140, 1240, 1340, 1440,1540, 1640, 1740 can provide a dual function of both compressingactuation element guides and routing cleaning fluid to various actuationelement guides, such as from a single inlet in the block.

Structures to Set and/or Adjust Compression of Actuation Element Guideswith Instrument Shaft

The various exemplary embodiments described herein contemplate otherstructures for blocks to compress actuation element guides. Turning toFIG. 21, an exemplary embodiment of a proximal portion 1900 of aninstrument shaft is depicted. As depicted in the exemplary embodiment ofFIG. 21, instrument shaft portion 1900 includes a roll gear 1906 so thatinstrument shaft portion 1900 may be rotated about its longitudinal axis1902, such as along the directions indicated by arrows 1904 in FIG. 21.Instrument shaft portion 1900 includes a proximal block 1930 to compressone or more actuation element guides 1950, such as according to theexemplary embodiments of FIGS. 4-6, 9, and 10. As depicted in FIG. 22,proximal block 1930 may include one or more passages 1932 correspondingto the number of actuation elements (not shown) extending throughproximal block 1930 and through the one or more actuation element guides1950.

To compress the one or more actuation element guides 1950, proximalblock 1930 may be fixed to an interior surface 1903 of instrument shaftportion 1900. For example, proximal block 1930 is connected to a fitting1940 that is fixed to instrument shaft portion 1900. Fitting 1940 isfixed to instrument shaft portion 1900 by welding fitting 1940 toinstrument shaft portion 1900, according to an exemplary embodiment. Forexample, fitting 1940 can be welded to instrument shaft portion 1900 byirradiating outer radial surface 1909 of instrument shaft portion 1900,which may be made of a transparent or translucent material, such as, forexample, PEEK or another polymer that is transparent or translucent,with a laser so the laser passes through instrument shaft portion 1900and impinges upon fitting 1940. In such an embodiment, fitting 1940 ismade of a material that is heated by the laser, such as, for example,PEEK or another polymer having an opaque color, according to anexemplary embodiment. However, other methods may be used to fix fitting1940 to instrument shaft portion 1900, such as by using fasteners, afriction fit construction, and other methods familiar to one of ordinaryskill in the art.

According to an exemplary embodiment, proximal block 1930 has a frictionfit connection with fitting 1940. As shown in the exemplary embodimentof FIG. 22, proximal block 1930 has a sloped outer radial surface 1934with respect to instrument axis 1902 and fitting 1940 has a sloped innerradial surface 1944. According to an exemplary embodiment, the slope ofouter radial surface 1934 of proximal block 1930 forms an angle 1946ranging, for example, from about 5 degrees to about 25 degrees withrespect to instrument axis 1902. According to an exemplary embodiment,the slope of inner radial surface 1944 of fitting 1940 forms an angle1946 ranging, for example, from about 2 degrees to about 10 degrees withrespect to instrument axis 1902. According to an exemplary embodiment,proximal block 1930 is inserted within central aperture 1948 of fitting1940 (shown in FIG. 23) to fix proximal block 1930 to instrument shaftportion 1900, such as via the connection between fitting 1940 andinstrument shaft portion 1900. At least one of proximal block 1930 andfitting 1940 may include a split along axis 1902 to facilitate changesin the diameter of proximal block 1930 and/or fitting 1940 as fitting1940 and proximal block 1930 are placed in set positions within theinstrument shaft.

Proximal block 1930 and the one or more actuation element guides 1950can be sealed to one another to facilitate flushing of cleaning fluidthrough the one or more actuation element guides 1950 so that cleaningfluid entering proximal block 1930 via passages 1932 is directed into aninterior of actuation element guides 1950. For example, proximal block1930 is made of a metal, such as a stainless steel or a plastic, withthe metal or plastic material of proximal block 1930 sealing to the oneor more actuation element guides 1950. In another example, proximalblock 1930 includes one or more seals (not shown), such as, for example,an elastomer seal, that seals with the one or more actuation elementguides 1950, as discussed above with regard to the exemplary embodimentof FIG. 22. According to an exemplary embodiment, passages 1932 may bedimensioned to permit both actuation elements and cleaning fluid toenter proximal block 1930 via passages 1932.

According to an exemplary embodiment, one or more actuation elementguides 1950 are mounted within proximal block 1930 to compress the oneor more actuation element guides 1950 between proximal block 1930 and adistal block (not shown), as discussed above with regard to theexemplary embodiment of FIGS. 4-6, 9, and 10. Thus, an amount ofcompression of the one or more actuation element guides 1950 may be setand/or adjusted, such as during assembly of an instrument and/or duringreprocessing of an instrument. To provide a predetermined amount ofcompression to the one or more actuation element guides 1950, outerradial surface 1942 of fitting 1940 and at least a portion of interiorsurface 1903 of instrument shaft portion 1900 are sloped a desiredamount, according to an exemplary embodiment. For example, each outerradial surface 1942 and interior surface 1903 (e.g., a portion ofinterior surface 1903 where fitting 1940 is installed) have an angle1943 ranging from, for example, about 2 to about 10 with respect toinstrument axis 1902. According to an exemplary embodiment, a method ofmanufacturing an instrument may include mounting one or more actuationelement guides 1950 within proximal block 1930 within instrument shaftportion 1900 and installing fitting 1940 between proximal block 1930 andinterior surface 1903 of instrument shaft portion 1900 so that fitting1940 is wedged between proximal block 1930 and surface 1903.Subsequently, fitting 1940 is fixed to surface 1903 to maintain apredetermined amount of compression of the at least one actuationelement guide 1950.

Reprocessing of Instrument with Shafts that Engage with Structures toSet and/or Adjust Compression of Actuation Element Guides

According to an exemplary embodiment, instrument shaft portion 1900 isconfigured to receive cleaning fluid to facilitate reprocessing of aninstrument including instrument shaft portion 1900. As depicted in theexemplary embodiment of FIGS. 21-23, a bushing 1910 is connected toinstrument shaft portion 1900 to supply cleaning fluid to instrumentshaft portion 1900. For instance, a tube 1912 may be connected tobushing 1910 and to a flush port (not shown) to receive cleaning fluid,as discussed above.

Due to the connection between fitting 1940 and instrument shaft portion1900, as well as between the connection between proximal block 1930 andfitting 1940, the one or more actuation element guides 1950, proximalblock 1930, and fitting 1940 rotate with instrument shaft portion 1900about axis 1902, such as when a rolling input is made to roll gear 1906.Because tube 1912 is connected to a flush port, such as a flush portlocated in a force transmission mechanism (not shown) of an instrumentincluding instrument shaft portion 1900, tube 1912 and bushing 1910 donot rotate with instrument shaft portion 1900 about axis 1901.Therefore, bushing 1910 is configured to provide a rotary seal betweenbushing 1910 and instrument shaft portion 1900 to permit instrumentshaft portion 1900 to rotate relative to bushing 1910 and tube 1912,while permitting cleaning fluid 1960 to be supplied through tube 1912and bushing 1910 to instrument shaft portion 1900. Further, by providinga cleaning fluid connection between tube 1912 and instrument shaftportion 1900 via bushing 1910 instead of proximal block 1930, proximalblock 1930 may utilize a simple construction that does not includemanifold passages to route the cleaning fluid from a single fluid inletto various actuation element guides 1950 extending through proximalblock 1930. According to an exemplary embodiment, tube 1912 and bushing1910 may be made of, for example, a polymer or a metal, such as astainless steel or another alloy familiar to one of ordinary skill inthe art.

Bushing 1910 also may include one or more seals 1914 (e.g., elastomerseals) respectively mounted within grooves 1913 of bushing 1910 to forma seal between bushing 1910 and an outer radial surface 1909 ofinstrument shaft portion 1900. Seals 1914 are configured to fluidicallyseal against outer radial surface 1909, even as instrument shaft portion1900 rotates relative to bushing 1910. As shown in FIGS. 22 and 23,bushing 1910 may include an annular manifold 1916 located between seals1914, along an axial direction (e.g., proximal-distal direction) ofinstrument shaft portion 1900. Annular manifold 1916 may surroundinstrument shaft portion 1900 so that cleaning fluid 1960 supplied tomanifold 1916 via tube 1912 flows about an outer surface of instrumentshaft portion 1900 until the cleaning fluid 1960 reaches a fluid inlet1901 and flows into an interior chamber 1907 within instrument shaftportion 1900, as depicted in FIG. 22.

Instrument shaft portion 1900 includes a seal block 1920 to directcleaning fluid 1960 into the one or more passages 1932 of proximal block1930 and respective actuation element guides 1950. Seal block 1920includes one or more passages 1922 corresponding to the number ofactuation elements (not shown) extending through seal block 1920 andproximal block 1930. Seal block 1920 seals with the actuation elements.According to an exemplary embodiment, seal block 1920 is made of ametal, such as stainless steel, that contacts and seals with theactuation elements extending through seal block 1920. According toanother exemplary embodiment, seal block 1920 includes seals (e.g.,elastomer seals) that engage and seal with the actuation elements,similar to the exemplary embodiment of FIG. 22. To hold seal block 1920in position, seal block 1920 can be fixed to inner surface 1903 ofinstrument shaft portion 1900. For example, surface 1924 of seal block1920 and inner surface 1903 of instrument shaft portion 1900 are slopedat an angle 1905 ranging, for example, from about 1 degree to about 7degrees with respect to instrument axis 1902 to provide a friction fitbetween seal block 1920 and instrument shaft portion 1900.

Due to the sealed arrangement between seal block 1920 and instrumentshaft portion 1900, between fitting 1940 and instrument shaft portion1900, and between proximal block 1930 and fitting 1940, cleaning fluidentering chamber 1907 from bushing 1910 is forced through the one ormore passages 1932 of proximal block 1930 and into the one or moreactuation element guides 1950 compressed by proximal block 1930. As aresult, the cleaning fluid 1960 flows through an interior of the one ormore actuation element guides 1950 along an axial direction of theinstrument until the cleaning fluid reaches a distal block (not shown),where the cleaning fluid 1960 exits the one or more actuation elementguides 1950 and flows around an exterior of the one or more actuationelement guides 1950 to reprocess an interior of instrument shaft portion1900 before exiting instrument shaft portion 1900, such as via flushexit port 1908.

Additional Structures to Set and/or Adjust Compression of ActuationElement Guides with Instrument Shaft

Other instrument arrangements are contemplated by the various exemplaryembodiments described herein. Turning to FIG. 24, an exemplaryembodiment of a proximal portion 2200 of an instrument shaft isdepicted. According to an exemplary embodiment, proximal portion 2200 ofinstrument shaft includes a proximal block 2230 one or more actuationelement guides 2250 are mounted to and a fitting 2240 that proximalblock 2230 engages with, as described above with regard to FIGS. 21-23.According to an exemplary embodiment, proximal block 2240 includes asloped outer radial surface 2232 and fitting 2240 includes a slopedinner radial surface 2244, as discussed above with regard to theexemplary embodiment of FIGS. 21-23. Fitting 2240 is fixed to shaft2200, as discussed above with regard to the exemplary embodiment ofFIGS. 21-23, except that fitting 2240 includes a threaded portion 2242and an inner radial surface 2203 of shaft portion 1900 includes acorresponding threaded portion 2202 to facilitate setting and/oradjusting a predetermined amount of compression to the one or moreactuation element guides 2250, according to an exemplary embodiment. Forexample, the position of fitting 2240 and proximal block 2230 movedalong directions 2260 in the exemplary embodiment of FIG. 24 by screwingfitting 2240 along threaded portion 2202 to set and/or adjust apredetermined amount of compression to the one or more actuation elementguides 2250.

FIG. 25 depicts an exemplary embodiment of a proximal portion 2300 of aninstrument shaft that includes a proximal block 2330, a fitting 2340,and one or more actuation element guides 2350 mounted to proximal block2330. Shaft portion 2300 and fitting 2340 respectfully include threadedportions 2302, 2344, as discussed above with regard to the exemplaryembodiment of FIG. 24, to facilitate setting and/or adjusting an amountof compression of the one or more actuation element guides 2350.Proximal block 2330 and fitting 2340 differ by not including slopedradial surfaces. Instead, proximal block 2330 includes a flange 2332 toengage with fitting 2340, according to an exemplary embodiment. As aresult, when the one or more actuation element guides 2350 apply a forceto proximal block 2330 along direction 2360 in the exemplary embodimentof FIG. 25, proximal block 2330 is forced against fitting 2340 tomaintain a position of proximal block 2330 relative to fitting 2340.

Although the various exemplary embodiments described herein contemplateincluding the various cleaning structures described herein, a surgicalinstrument may lack the cleaning structures described. For example, asurgical instrument may be a single-use surgical instrument andtherefore lack structures to facilitate cleaning of the instrument.

Actuation Element Guides Including Portions with Different Amounts ofTwist

Other structures are contemplated by the various exemplary embodimentsdescribed herein. For example, the proximal block 430 of FIG. 4 has beendescribed as being located at a proximal portion 412 of shaft 400, suchas by being disposed within a force transmission mechanism of aninstrument. As a result, actuation element guides 420, 422, 424 may bepre-compressed along substantially their entire lengths. According toanother exemplary embodiment, the actuation element guides may bepre-compressed along a portion of their axial lengths. Turning to FIG.26, an exemplary embodiment of a bundle 1800 of actuation element guidesis schematically depicted. As shown in the exemplary embodiment of FIG.26, bundle 1800 may include a first portion 1810 of straight actuationelement guides and a second portion 1820 of twisted element guides(e.g., twisted about a longitudinal axis 1870 of bundle 1800). Firstportion 1810 may have a length corresponding to a portion of aninstrument (that includes bundle 1800) not substantially bent when theinstrument is inserted into a cannula having a curved section, whilesecond portion 1820 may have a length corresponding to the curvedsection (e.g., curved section 322 of cannula 320 in FIG. 3) of thecannula so the pre-compressed actuation element guides of sectionportion 1820 may compensate for changes in length of actuation elementsextend through the actuation element guides of bundle 1800 when theinstrument is bent in the curved section of the cannula.

First portion 1810 may extend, for example, from a proximal end 1802 ofbundle 1800 and join second portion 1820, which extends to a distal end1804 of bundle 1800. According to an exemplary embodiment, proximal end1802 may be disposed within a force transmission mechanism of aninstrument and distal end 1804 may be disposed within a distal portionof an instrument. The actuation element guides of first portion 1810 andsecond portion 1820 may be connected to one another so that actuationelements extending through the straight actuation element guides offirst portion 1810 extend through corresponding actuation element guidesof second portion 1820. According to an exemplary embodiment, bundle1800 may include a proximal block 1830 and a distal block 1840 topre-compress actuation element guides of second portion 1820, such asaccording to the exemplary embodiments of FIGS. 9-17, except that bundle1800 may include a fitting 1832 holding actuation element guides offirst portion 1810 in a straight configuration but permitting actuationelement guides of second portion 1820 to assume non-linear shapes intheir pre-compressed state. According to an exemplary embodiment,proximal portion 1802 and/or distal portion 1804 of bundle 1800 may befixed to an instrument including bundle 1800, so that when the shaft ofthe instrument including bundle 1800 is rolled in the directionsindicated by arrows 1872 about axis 1870, both portions 1810, 1820 ofbundle 1800 are also rolled. According to an exemplary embodiment,proximal block 1830 is fixed to an instrument, with portions 1810 and1820 free to move relative to proximal block 1830. For example, portions1810 and 1820 twist relative to proximal block 1830, such as when distalblock 1840 is fixed to an instrument shaft (not shown) and rolls withthe instrument shaft.

The exemplary embodiments and methods described herein have beendescribed as being utilized with surgical instruments for teleoperatedsurgical systems. However, the exemplary embodiments and methodsdescribed herein may be used with other surgical devices, such aslaparoscopic instruments and other hand held instruments. Further, theexemplary embodiments and methods may be employed in other applicationsthat use remotely actuatable components. For instance, the exemplaryembodiments described herein may be used in devices used for pipeinspection and other devices utilizing remote access via teleoperationor manual actuation.

By providing pre-compressed actuation element guides as described in thevarious exemplary embodiments herein, the actuation element guides maycompensate for changes in length of actuation elements extending throughthe actuation element guides, such as when the actuation element guidesextend through a curved section of a cannula. As a result, changes oflength of the actuation elements is minimized or eliminated, which couldotherwise interfere with the functioning of the actuation elements toactuate an instrument, such as, for example, to actuate an end effectorand/or wrist of an instrument.

Further modifications and alternative embodiments will be apparent tothose of ordinary skill in the art in view of the disclosure herein. Forexample, the systems and the methods may include additional componentsor steps that were omitted from the diagrams and description for clarityof operation. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the present teachings. It isto be understood that the various embodiments shown and described hereinare to be taken as exemplary. Elements and materials, and arrangementsof those elements and materials, may be substituted for thoseillustrated and described herein, parts and processes may be reversed,and certain features of the present teachings may be utilizedindependently, all as would be apparent to one skilled in the art afterhaving the benefit of the description herein. Changes may be made in theelements described herein without departing from the spirit and scope ofthe present teachings and following claims.

It is to be understood that the particular examples and embodiments setforth herein are non-limiting, and modifications to structure,dimensions, materials, and methodologies may be made without departingfrom the scope of the present teachings.

Other embodiments in accordance with the present disclosure will beapparent to those skilled in the art from consideration of thespecification and practice of the invention disclosed herein. It isintended that the specification and examples be considered as exemplaryonly, with the claims being entitled to their full breadth and scope,including equivalents.

What is claimed is:
 1. A surgical instrument, comprising: a shaftextending along a longitudinal axis, the shaft comprising a bendableportion; a force transmission mechanism coupled to the shaft; an endeffector coupled to the shaft; an actuation element extending along theshaft and operably coupling the force transmission mechanism to the endeffector, the actuation element being configured to transmit anactuation force from the force transmission mechanism to the endeffector; and an actuation element guide extending along at least thebendable portion of the shaft, wherein the actuation element guidedefines a lumen in which the actuation element is received; a firstblock at a first end of the actuation element guide; and a second blockat a second end of the actuation element guide opposite the first end;wherein one of the first or second blocks is adjustably positionable, aposition being set by any of set screws, a wedge, complementary threadedengagement features, a ratchet structure, a clamping mechanism, or aflange on the first or second block engageable with a mount, andwherein, in the absence of both a bending of the bendable portion of theshaft and the actuation force applied to the actuation element, theactuation element guide is under a longitudinal pre-compression forceapplied to the actuation element guide by the first block and the secondblock.
 2. The surgical instrument of claim 1, wherein the shaftcomprises an inner wall defining a hollow, open space within the shaftbetween the inner wall and the actuation element guide.
 3. The surgicalinstrument of claim 1, wherein the actuation element guide is tubular.4. The surgical instrument of claim 1, wherein: one of the first blockor the second block is positionable relative to the shaft; and an amountof the longitudinal pre-compression force is based on a position of thefirst and second blocks relative to the shaft.
 5. The surgicalinstrument of claim 1, wherein the actuation element guide is laterallyunconstrained within the shaft between the first block and the secondblock.
 6. The surgical instrument of claim 1, wherein at least a portionof the actuation element guide has a non-linear shape in a straightconfiguration of the shaft.
 7. The surgical instrument of claim 1,further comprising a wrist between the shaft and the end effector.
 8. Asurgical instrument, comprising: a shaft extending along a longitudinalaxis, the shaft comprising a bendable portion; a force transmissionmechanism coupled to the shaft; an end effector coupled to the shaft; anactuation element extending along the shaft and operably coupling theforce transmission mechanism to the end effector, the actuation elementbeing configured to transmit an actuation force from the forcetransmission mechanism to the end effector; and an actuation elementguide extending along at least the bendable portion of the shaft,wherein the actuation element guide defines a lumen in which theactuation element is received; a first block at a first end of theactuation element guide; and a second block at a second end of theactuation element guide opposite the first end; wherein one of the firstor second blocks is adjustably positionable, a position being set by afitting fixed to an interior surface of the shaft and engageable withthe one of the first or second blocks, wherein the fitting is any of asloped surface engageable with a complementary sloped surface of the oneof the first or second blocks, or a fitting engageable with a flange onthe one of the first or second blocks, and wherein, in the absence ofboth a bending of the bendable portion of the shaft and the actuationforce applied to the actuation element, the actuation element guide isunder a longitudinal pre-compression force applied to the actuationelement guide by the first block and the second block.
 9. The surgicalinstrument of claim 8, wherein the shaft comprises an inner walldefining a hollow, open space within the shaft between the inner walland the actuation element guide.
 10. The surgical instrument of claim 8,wherein the actuation element guide is tubular.
 11. The surgicalinstrument of claim 8, wherein: one of the first block or the secondblock is positionable relative to the shaft; and an amount of thelongitudinal pre-compression force is set based on a position of thefirst and second blocks relative to the shaft.
 12. The surgicalinstrument of claim 8, wherein the actuation element guide is laterallyunconstrained within the shaft between the first block and the secondblock.
 13. The surgical instrument of claim 8, wherein at least aportion of the actuation element guide has a non-linear shape in astraight configuration of the shaft.
 14. The surgical instrument ofclaim 8, wherein the fitting is fixed to the interior of the shaft via aweld.
 15. A surgical instrument, comprising: a shaft extending along alongitudinal axis, the shaft comprising a bendable portion; a forcetransmission mechanism coupled to the shaft; an end effector coupled tothe shaft; an actuation element extending along the shaft and operablycoupling the force transmission mechanism to the end effector, theactuation element being configured to transmit an actuation force fromthe force transmission mechanism to the end effector; and an actuationelement guide extending along at least the bendable portion of theshaft, wherein the actuation element guide defines a lumen in which theactuation element is received; wherein the actuation element guideextends straight along a first length of the actuation element guide,and wherein the actuation element guide extends in a twisted path abouta longitudinal axis of the actuation element guide along a second lengthof the actuation element guide.
 16. The surgical instrument of claim 15,wherein the second length of the actuation element guide extends alongthe bendable portion of the shaft.
 17. The surgical instrument of claim15, further comprising a fitting configured to hold the actuationelement guide straight along the first length of the actuation elementguide and in the twisted path along the second length of the actuationelement guide.
 18. The surgical instrument of claim 17, wherein thefitting is positioned over a portion of the actuation element guidealong which the actuation element guide transitions from the firstlength to the second length.
 19. The surgical instrument of claim 18,wherein the actuation element guide is one of a plurality of actuationelement guides, each comprising a first length along which eachactuation element guide extends straight and a second length along whicheach actuation element guide extends in a twisted path.
 20. The surgicalinstrument of claim 17, wherein the fitting is fixed to an interiorsurface of the shaft via a weld.